Apparatus for receiving and projecting televised images in synchronism with sound



June 30, 1936. L. DE FOREST APPARATUS FOR RECEIVING AND PROJECTING TELEVISED IMAGES IN SYNCHRONISM WITH SOUND Original Filed April 24, 1951 INVENTOF? LEE DE F0955? j fi.

ATTORNEY Patented June 30, 1936 UNITED STATES PATENT OFFICE APPARATUS FOR RECEIVING AND PRO- JECTING TELEVISED IMAGES IN SYN- CHRONISM WITH SOUND Lee de Forest, Los Angeles, Calif., assignor to American Television Laboratories, Inc., a corporation of Delaware 12 Claims.

This invention relates in a general way to the art of projecting, upon a screen, motion pictures which are recorded on a moving film from television impulses, and reproducing sound in synchronism with the projected pictures, such sound having its source in impulses which originate at the television transmitter.

In my copending application, Serial No. 532,454, filed April 24, 1931, of which this is a division, I describe means for recording pictures upon a moving film from television impulses, and although the invention of my copending application permits the immediate projection of the pictures without any intermediate treatment of the film, there is necessarily a delay of several seconds between the time at which the television impulses are received and the time at which the picture passes through the projector. It is necessary, therefore, in reproducing sound, which originates at the television transmitter, so as to give the illusion of talking pictures, to introduce a time interval between the time at which the sound impulses are received by the sound impulse receiver and the time at which such impulses act upon the sound amplifier associated with the loud speaker. It is important of course that this time interval correspond to the time required in recording the pictures upon the film and advancing the film through the projector.

It therefore becomes a primary object of this invention to produce a sound reproducing system which is associated with means for recording and projecting television pictures, and which has embodied therein means for delaying the reproduction of the sound impulses in the loud speaker subsequent to their reception.

The device contemplated by this invention consists in a general way of the combination of a television receiver and projector of the type referred to above with a receiver adapted to receive sound modulated electrical impulses which may be of the radio or wire type. The receiver is associated with an electrically sensitive element hereinafter referred to as a first element, which is preferably of the electromagnetic type, and is adapted to be acted upon in a suitable manner by the received and preferably amplified sound controlled impulses. In addition to this first element, I employ, what I may term a second electrically sensitive and preferably electromagnetic element which is adapted to receive or to be acted upon by sound controlled impulses coming from the first element through a suitable connecting or delivering mechanism. The second element is connected to the power amplifier of a loud speaker and the connecting mechanism, just referred to, is adjusted so that the time interval consumed in delivering impulses from the first element to the second element, is the same as the time required for the televised image to be recorded on a moving film and passed through a projector.

It is a further object of this invention to produce a device of the class described which is of simple form and construction and is capable of adjustment to bring the sound and the projected motion picture into synchronism.

The details in the construction of a preferred form of my invention, together with other objects attending its production will be best understood from the following description of the accompanying drawing which is a diagrammatic view illustrating the construction of a preferred form of my invention.

More particularly describing the invention, reference numeral I I indicates a specially coated film of the motion picture type upon which individual televised images are adapted to be etched as pietures through the medium of an oscillating high frequency discharge modulated by television impulses which passes between a discharge strip I2 and rapidly moving discharge points I3 on a rotating disk I4.

The oscillating high frequency current just referred to, is delivered to the strip I2 and the discharge points I3 through conductors I5 from an oscillator generally indicated by reference numeral I6, and the current is modulated by impulses received in a television receiver generally indicated by reference numeral I I.

Since the apparatus for recording the pictures upon the film II forms the subject matter of my copending application, Serial No. 532,454, this apparatus will receive no further consideration in this case.

The film I I, after the pictures mentioned above have been etched thereon, passes over sprockets I8 and I9 to a projector generally indicated by reference numeral 20 from which the images are projected upon a screen of the usual type indicated by reference numeral 2|.

Although the film, when treated in accordance with the invention of my copending application, can be passed immediately to the projector 20, it is obvious, as pointed out above, that there will be a delay of several seconds before the televised image is projected upon the screen, and as was also pointed out above, the present invention is concerned primarily with means for reproducing sound impulses, which have their source at the television transmitter, in synchronism with the projected picture. When these sound impulses are in the nature of radio impulses, the receiving and reproducing means comprise an antenna 25 which may also be used for the reception of the television impulses. This antenna is connected with an ordinary radio receiver 26, which in turn is connected through an audio amplifier 21 to, what I may term, a first electrically sensitive impulse receiving element 28.

The element 28 in this form of my invention consists of an ordinary speaker head, the armature 29 of which, instead of being associated with the usual type of diaphragm, is connected with a long coiled wire 31! supported in any suitable manner as indicated by reference numeral 3|.

The wire 30 may be composed of steel or bronze or other suitable material and has its other end connected with an armature 32 of a pick-up head 33 which, I will hereinafter refer to as a second element. The head 33 is shown as being connected through conductors 34 with a power amplifier 35 which in turn is connected with a loud speaker 36, By means of the coiled wire 30, I am able to obtain any desired lapse of time between the application of the sound impulses at the armature 29 and the taking off of such impulses at the armature 32.

This time lapse depends upon the mechanical characteristics of the transmitting wire, that is, its overall length, its unit mass, its state of tension, etc., and I have found that by such means it is not difficult to introduce the three or four seconds lag between the receipt of the sound impulses from a distant transmitting station and its reproduction in the loud speaker .36 so as to bring the sound in perfect synchronism with the delayed film picture which is being projected upon the screen in the manner outlined above.

Although I have confined the description of my invention to one specific mechanism for delaying the reproduction of sound after its reception so as to bring the same into synchronism with the projected pictures, it will be apparent to those familiar with the art, that the invention in its broader aspects comprises the combination of a television picture projecting system with a sound reproducing system which includes a lagging device or a first element and a second element in the sound receiving amplifying and reproducing system, such elements being associated with means interposed therebetween for delaying the delivery of sound impulses from the first element to the second element over a predetermined interval of time.

It is to be understood therefore that while I have herein described and illustrated one preferred form of my invention, that the invention is not limited to the precise construction described above, but includes within its scope whatever changes fairly come within the spirit of the appended claims.

I claim as my invention:

1. A television and sound receiving and reproducing system embodying: means for receiving and amplifying impulses coming from a television transmitter; means controlled by said television impulses for. recording upon a moving film, pictures corresponding with the transmitted images; means for projecting said pictures upon a screen; means for independently receiving and amplifying impulses coming from a, sound transmitter; and means for reproducing the sound in synchronism with the projected pictures, the last mentioned means including a sound-delaying sound-conducting member.

2. A television and sound receiving and reproducing system embodying: means for receiving and amplifying impulses coming from a television transmitter; means controlled by said television impulses for recording upon a moving film, pictures corresponding with the transmitted images; means for projecting said pictures upon a screen; means for receiving and amplifying impulses coming from a sound controlled transmitter; and means for reproducing the sound in syn- 1 chronism with the projected pictures, said last mentioned means comprising a speaker head, a pick-up head, and means interposed between said heads for delivering sound impulses received by said speaker head to said pick-up head after a predetermined. time interval.

3. A television and sound receiving and reproducing system embodying: means for receiving and amplifying impulses coming from a television transmitter; means controlled by said television impulses for recording upon a moving film, pictures corresponding with the transmitted images; means for projecting said pictures upon a screen; means for independently receiving and amplifying impulses coming from a sound trans mitter; and means for reproducing the sound in synchronism with the projected pictures, said last mentioned means comprising a speaker head, a pick-up head, an elongated flexible member connecting the armatures of said heads and a loud speaker connected with said pick-up head.

4. A television and sound receiving and reproducing system embodying: means for receiving and amplifying impulses coming from a television transmitter; means controlled by said television impulses for recording upon a moving film, pictures corresponding with the transmitted images; means for projecting said pictures upon a screen; means for receiving impulses coming from a sound controlled transmitter; and means for reproducing the sound impulses in synchronism with the projected pictures, said last mentioned means comprising a first element adapted to receive impulses from said sound impulse receiving means, a second element, associated with a loud speaker, and means interposed between said first and second elements for delivering impulses received by the first element to the second element after a predetermined time interval, the last mentioned means including a sound-delaying sound-conducting member.

5. A television and sound receiving and reproducing system embodying: means for receiving television impulses; means controlled by said television impulses for recording pictures upon a moving film; means for projecting said pictures upon a screen; means for receiving sound controlled impulses simultaneously with the reception of said television impulses; and means for reproducing sound from said sound impulses in synchronism with the projected pictures com prising a first element adapted to receive impulses from said sound impulse receiving means, a second element associated with a loud speaker, and sound conducting means interposed between said first and second elements for delivering impulses received by the first element to the second element after a predetermined time delay.

6. The combination of a television picture projector, a sound reproducing device, and an electro-mechanical sound lagging device, said lagging device including a sound conducting member for delaying the transmission of sound impulses a predetermined time interval.

7. The combination of a television picture pro- 7 jector, a sound reproducing device, and an electro-mechanical sound lagging device adapted to receive sound controlled impulses and reproduce such impulses in synchronism with the projected television pictures, said lagging device including a sound conducting member for delaying the transmission of sound impulses a predetermined time interval.

8. In a system for transmitting scenic representations and accompanying sounds and reproducing them in proper time relation, the combination of means for receiving image impulses, means for utilizing said impulses to reproduce the scenic representations on a motion picture film, means for receiving currents representing the sounds to accompany said scenes, a channel for continuously translating the last mentioned currents into audible vibrations, said channel comprising means for delaying said translation between two points of said channel a predetermined interval after the time of reception of the sound impulses.

9. A system according to claim 8, in which the means for delaying the transmission in said channel comprises a, sound conducting member having a sound transmission delay characteristic.

10. A system according to claim 8 in which the means in said channel for delaying the transmission includes a pair of vibrating members coupled together through a sound-conducting, transmission-delaying member.

11. A system according to claim 8 in which the said channel comprises a device for translating the received sound currents into mechanical vibrations at one point, and means for retranslating said vibrations into electrical currents at another point, the last mentioned means including a sound-conducting, transmission-delaying member.

12. The combination of a television picture projector, a sound reproducing device and. an electro-mechanical sound lagging device adapted to receive sound controlled impulses and reproduce such impulses in synchronism with the projected television pictures, said lagging device comprising means for delaying said reproduction of said sound a predetermined interval after the time of reception of the sound impulses.

LEE DE FOREST.

DISCLAIM ER 2,045,570.Lee de Forest, Los Angeles, Calif. APPARATUS FOR RECEIVING AND PROJECTING TELEVISED IMAGES IN SYNCHRONISM WITH SOUND. Patent dated June 30, 1936. Disclaimer filed October 14, 1938, by the assignee, American Television Laboratories, Inc. Hereby enters this disclaimer to claims 8 and 12 of said patent.

[Ofiicial Gazette November 8, 1988.]

DISCLAIMER 2,04=5,570.Lee de Forest, Los Angeles, Calif. APPARATUS FOR RECEIVING AND PROJECTING TELEVISED IMAGES IN SYNCHRONISM WITH SOUND. Patent dated June 30, 1936. Disclaimer filed October 14, 1938, by the assignee, American Television Laboratories, Inc. Hereby enters this disclaimer to claims 8 and 12 of said patent.

[Oflicial Gazette November 8, 1 988.] 

